1. Field of the Invention
The present invention relates to a fault-detecting apparatus and method used in connection with an active solar system.
2. Description of the Prior Art
In active solar systems, including water systems and antifreeze systems, a number of faults can occur relating to the operation of the system. Such malfunctions include actual system failures which can be defined as failure of the solar energy-absorbing fluid (including but not limited to water and antifreezes) to circulate in the system, and failure to protect portions of the system and/or the solar fluid from freezing. Additionally, other failures can be defined relating to improper operation of the system wherein such operation leads to a loss of collected energy or are indicative of potential serious system problems including: the failure of the system to shut down when appropriate, e.g., sunlight not being available; failure to protect the storage tank of the system from overheating; failure due to excessive pipe corrosion; and failure due to pipe scaling, which is primarily the result of the high mineral content of water.
It would be advantageous to know when such failures occur so that the user or owner of the solar system is alerted to potentially expensive failures and is informed when the system is not operating properly. Such fault detection in an active solar system, such as a solar domestic hot water system, is particularly important because a conventional domestic hot water system normally is used as a backup or auxiliary system to the solar domestic hot water system. As a result, if the solar domestic hot water system fails, the user may only be minimally aware, if at all, of such a failure because the auxiliary system will continue to provide the necessary hot water.
To alleviate this serious deficiency associated with conventional active solar systems, such as the solar domestic hot water system, the present invention utilizes a fault detection system wherein the user is made aware of predetermined failures which can occur during the operation of the active solar system, and in particular the specific identity of the failure which has occurred. Based on this information, the user can take appropriate corrective action immediately thereby minimizing expensive solar system failures and enhancing the efficiency of the operation of the system. In contrast to conventional systems, as previously alluded to above, the user is made aware of the predetermined faults or failures even when a conventional hot water system is used as a back up system, and the hot water is still being provided to the user. In addition, because the present invention requires a manual resetting to remove a fault indication, even after a fault no longer exists, an indication is given to the user that a fault had occurred some time prior, as will be more fully explained hereinafter.
To continue, conventional control systems have been developed which sense predetermined conditions associated with a solar system to provide necessary controls in the operation thereof. Unfortunately, such control systems normally do not provide the desired capability of detecting the predetermined faults which can occur in an active solar system. The present invention, however, does achieve these desired results by monitoring predetermined conditions and making a determination as to whether predetermined faults have occurred. Moreover, it should be noted that the present invention does not even disclose or include a control system whereby control of the active solar system is effected. Instead, as just mentioned, it is directed to alerting the owner or user of the system of the predetermined failures. Because the present invention is not concerned with controlling the operation of the active solar system, the complexity thereof is reduced advantageously over that normally found in conventional solar system controllers.
Against the foregoing background, it is therefore a general object of the present invention to provide a fault-detecting apparatus for applications in active solar systems which advantageously alerts the user thereof to the occurrence of predetermined solar system failures and the specific identities thereof.
It is another general object to provide a low-cost, substantially efficient, simplified, fault-detection system for active solar system applications.
It is a more specific object to provide a fault-detecting apparatus which can be used with either water or anitfreeze-type active solar systems.
It is still another specific object to provide a fault detecting system for active solar system applications which is enabled to indicate whether a number of predetermined failures associated with the active solar system have occurred, i.e., failure of the fluid to circulate in the system, failure of the system to shut down when predetermined conditions are present, failure to protect the collectors or pipes from freezing, failure to prevent overheating of the tank, failure due to excessive corrosion of pipe, and failure due to excessive scaling of pipe.
It is yet another specific object to provide a fault detecting apparatus for active solar system applications having a logic circuit which is enabled to give a visual indication as to whether or not predetermined faults associated with the system have occurred.
It is yet and still another specific object to provide a fault detecting system for active solar system applications which includes a means for manually resetting a fault indication to effect its removal.